Synthetic oil-soluble alkyl diphenylalkane sulfonates



Patented Dec. 2, 1952 SYNTHETIC OIL-SOLUBLE ALKYL DIPHENYLALKANE SULFONATES Samuel B. Lippincott, Westfield, Frederick Neil Baumgartner, Cranford, and Howard L. Yowell, Westfield, N. J., assignors to Standard Oil Development Companyga corporation of Delaware N Drawing. Application November 1, 1950, Serial No. 193,547

4 Claims. 1

This invention relates to improved oil-soluble sulfonic acids and their salts especially the alkali metal and alkaline earth metal salts.

It has now been found that certain mono-sulionated alkylated aromatic condensation products which are believed to be novel chemicals are extremely effective in those applications in which oil-soluble sulfonates are especially valuable such as lube oil detergents, anti-rusting compositions, etc. These alkylated diphenylalkane monosulfonates in which the total aliphatic carbon atoms number between 16 and 42 are therefore valuable adjuncts to the ever continuing search for synthetics of this nature.

The class of compounds of this invention are thus valuable textile and lubricating oil additives when added in an amount between about 0.1% up to as much as by weight of the oil. The

resulting compositions exhibit improved lubricat ing properties especially in heavy duty service such as encountered in diesel engines, aircraft engines, and the like. Oils containing the compounds of this invention have a detergent action on the parts of the engine that they lubricate and are capable of being used under increased loads and temperatures without causing seizure of bearings or sticking of piston rings by formation of varnish. Oils compounded with these sulfonates also act as rust preventative in the engine during periods of quiescence.

"Suitable typical compounds of the type of this invention which contain only 1 alkyl substituent on each of the phenyl groups are illustrated by the Formula I below:

FORMULA I wherein R and R." are alkyl radicals, which can be the same or difierent, R is an alkylene radical and X is a radical selected from the group consisting of hydrogen, alkali metals, alkaline earth metals and the nitrogen base radicals such as guanidine, ammonia, etc. Those compounds wherein R is an alkylene radical having from 1 to 10 carbon atoms, R and R" are alkyl radicals, which can be the same or different, having a total carbon atom number of at least 15, the total carbon atom number of R, R and R not exceeding 42, and X is sodium, calcium or barium are especially effective. When additional alkyl substituentsare attached to the phenyl groups it is desirable that the total number of aliphatic carbon atoms should be between 16 and 42. It is to be understood that the SOsX group can be attached toany of the vacant positions of either nucleus and the R and R" radicals, while usually in the para position relative to the R group, can also be in any vacant position of the particular benzene ring. Particularly effective and desirable compounds of the class of compounds of this invention are the his (do decylphenyl) methane, bis (nonylphenyl) methane, dodecylphenylmethylxylyldecane, and dodecylphenylmethylduryldecane sulfonic acids and their indicated salts such as the calcium sulfonates, etc.

Among other particular compounds that may be utilized for the purpose of this invention are the sulfonic acids of: bis(octadecylphenyl)methane, bis octadecylphenyl) hexane, octylphenylmethylphenyloctadecane, octylphenylheptylphenylmethane and bis(decylphenyl) ethane.

The compounds of this invention can be prepared in general by condensing 2 moles of the indicated alkylated aromatic compounds such as kerylbenzene (from alkylating benzene with chlorinated kerosene), polypropyltoluene (from alkylating toluene with tripropylene, tetraproylene, etc.), and octylnaphthalene (from alkylating naphthalene with 'diisobutylene) with a suitable aliphatic compound such as for example formaldehyde, acetaldehyde, etc., a chloromethyl ether such as chloromethyl ethyl ether or chloromethyl methyl ether, a dihalogenated aliphatic compound such as ethylene chloride, 1,3-dichloropropane, 1,4-dichlorobutane, 1,6-dichlorohexane, or other .difunctional compound such as allyl chloride or by other'conventional condensation reactions. The reaction itself is illustrated by Equations I and II below:

' 1101 R- none 3- 011201 EQUATION I EQUATION II The -bis(alkylated) compound is then sulfonated on an equimolar basis in the conventional manner. Sulfonating agents that may be em ployed include concentrated sulfuric acid, oleum,

sulfonyl chloride, sulfur dioxide and chlorine gas, sulfur trioxide, sulfur trioxide and liquid S02,

brom-and chlor-sulfonic acids, etc., and their mixtures.

In the sulfonation treatment the his- (alkylaryl) alkane product is treated with the sulfonating agent such as concentrated sulfuric acid. The oil soluble sulfonic acids which are predominantly in the organic layer are subsequently neutralized with usually caustic soda. The sodium soaps are then extracted with aqueous alcohol solutions such as 50% aqueous isopropyl alcohol, 50% aqueous ethyl alcohol, etc. These sodium salts are then converted in oils by a double decomposition reaction to the corresponding alkaline earth salts when it is desired to use the latter in lubricating oils. The acids may also be neutralized directly with calcium hydroxide, barium hydroxide, nitrogen bases, etc.

The following examples are given to illustrate this invention and include both the preparation of the compounds of this invention, their intermediates, and test results on their use as oil soluble detergents.

EXAMPLE I Preparation of dodecylphenylmethyl chloride A mixture of .92 (2 moles) grams of dodecylbenzene (from the alkylation of benzene with tetrapropylene) and 95 (1 mole) grams of chloromethyl ethyl ether at 40 C. was stirred while ml. of anhydrous stannic chloride was added. The temperature of the reaction mixture rose spontaneously to 58 C. and was maintained at this temperature for a total of two hours, 1 ml. of stannic chloride being added every half hour. The reaction mixture was poured into cold water and was washed three times with water and then with dilute sodium carbonate. The oil layer was dried with sodium carbonate. The mixture was then stripped under vacuum to remove anything boiling below detergent alkylate. The residue (496 g.) contained 3.46% chlorine. This indicat' ed that the reaction mixture now consisted of one-half mole of dodecylphenylmethyl chloride and one and one-half moles of dodecylbenzene.

EXAMPLE II Preparation of bis(dodecylphenyl) methane The reaction mixture from Example I was stirred at room temperature while 3 grams of aluminum chloride were added. The temperature rose from 26 C. to 32 C. spontaneously and then was heated to 40 C. for a total reaction time of two hours until the hydrogen chloride which was evolved rapidly at first was no longer liberated. The reaction mixture was washed with water several times and then with dilute potassium hydroxide. It was dried with anhydrous potassium hydroxide. The unreacted dodecylbenzene was stripped from the reaction mixture by distillation at reduced pressure, the pot temperature being raised to 200 at about 0.1 mm. Hg pressure. The amount of unchanged dodecylbenzene recovered was 265 g. The bis(dodecylphenyl) methane which remained in the distillation flask as a rather viscous oil amounted to 190 g. The molecular weight determined cryoscopically was 502 as compared to a theoretical molecular weight of 504.

EXAMPLE III Preparation of bis(dodecylphenyl) methane sodium sulfonate 101 grams of the bis(dodecylphenyl)methane from Example II and about 200 ml. of liquid sulfur dioxide were placed in a flask under a Dry Ice cooled reflux condenser. The mixture was stirred while 16.8 g. of liquid sulfur trioxide and 25 ml.

of liquid sulfur dioxide were added dropwise over a period of about five minutes. Stirring was continued for one-half hour and the sulfur dioxide was then allowed to evaporate while the reaction mixture came to room temperature. The last of the sulfur dioxide was removed by applying partial vacuum. The residue was taken up in 50% aqueous isopropyl alcohol (400 ml.) and was neutralized with sodium carbonate. The unsulfonated oil was extracted from the resulting mixture by extraction with petroleum ether. The aqueous alcohol layer was saturated with sodium carbonate at about 50 C. and allowed to cool to room temperature. The alcoholic solution was separated from the aqueous layer and evaporated to dryness, finishing in a vacuum oven at about 50 C. The dry product weighed 78 g. The sulfated ash was determined and found to be 16.1% indicating a combining weight 422 for the sulfonic acids.

EXAMPLE IV Bis(dodecyiphenyl) methane sodium sulfonate as an emulsifier A blend of 0.6 weight per cent of bis(dodecylphenyl)methane sodium sulfonate in a heavy duty motor oil base was thoroughly mixed with 20 weight per cent of water and allowed to stand for 72 hours. There was no indication of separation of layers at the end of this period. This indicates that the material is an excellent emulsifier.

EXAMPLE V Preparation of bis(dodecylpheuyl) methane calcium sulfonate A blend of 454 g. of bis(dodecylphenyl) methane sodium sulfonate in 950 g. of a light lubricating oil was agitated in the presence of a solution of 300 g. of calcium chloride in 1500 ml. of water and heated to the boiling point. The mixture was kept hot while the layers were allowed to separate and the brine layer was drawn off. The oil was then heated to C. with stirring in the presence of 20 g. calcium hydroxide until dry and was filtered while hot using a diatomaceous earth as a filter aid. The resulting blend was shown by analysis to be 26 weight per cent calcium sulfonate and possessed an alkalinity equivalent to 7.5 mg. KOH per g. of blend. The molecular weight of the calcium sulfonate was 800.

EXAMPLE VI Behavior of bis(dodecylphenyl) methane calcium sulfonate in the carbon dispersion test The bis(dodecylphenyl)methane calcium sulfonate was tested for colloidal dispersing eiTect in the Carbon Dispersion Test, and was shown to be equivalent in this respect to commercially available oil soluble calcium sulfonates as may be seen in the following table:

CARBON DISPERSION TE ST The test is conducted as follows:

EXAMPLE VII Behavior of bis(dodecylphenyl)methane calcium sulfonate in engine tests Lauson Engine Tests were made on a series of lubricating oils. The first, the control, was a lubricating oil containing some additives but no detergent additive. The second test was made with an oil of the same composition to which had been added 3 weight per cent of bis(dodecylphenyl) methane calcium sulfonate. Two other oil compositions were tested, being the same in every respect except that commercially available oil-soluble calcium sulfonates (products A and B) were added in place of bis(dodecylphenyl)- methane calcium sulfate. The results of these tests are tabulated below and it is clear from these data that the product of this invention is a superior detergent additive for lubricating oils.

LAUSON ENGINE resr These results clearly indicate how the compounds of this invention minimize undesirable varnish and prevent bearing wear.

The lubricating oil composition prepared by the addition of the compounds of this invention may be further compounded if desired with other additives such as oxidation inhibitors and the like. Lubricating oils made in accordance with this invention are generally pale in color and show good stability especially at high temperatures.

t is to be understood that the invention is not limited to the specific examples which have been offered merely as illustrations since other derivatives can be prepared and modification may 6 be made without departing from the spirit of this invention.

What is claimed is: 1. As new chemicals, compounds correspond- 5 ing to the following formula:

SOaX

wherein R is an alkylene radical having from 1 to 10 carbon atoms, R and R." are alkyl radicals, which can be the same or different, having a total carbon atom number of at least 15, the total carbon atom number of R, R and R" not exceeding 42 and X is a radical selected from the group consisting of hydrogen, alkali metal, alkaline earth metal and acyclic nitrogen base radicals.

2. As a new chemical, bis(dodecylphenyl)- 2 methane calcium sulfonate corresponding to the formula 3. As a new chemical, bis(nonylpheny1)meth ane calcium sulfonate corresponding to the for- 4. As a new chemical bis(dodecylphenyl)methane sodium sulfonate corresponding to the formula MEMT r- I 012 2:

S03 Na SAMUEL B. LIPPINCOTT. 40 F. NEIL BAUMGARTNER.

HOWARD L. YOW'ELL.

REFERENCES CITED The following references are of record in the file of this patent: 

1. AS NEW CHEMICALS, COMPOUNDS CORRESPONDING TO THE FOLLOWING FORMULA: 